This invention relates to chemical milling or etching solution, and more particularly, it refers to chemical milling solutions for aluminum-lithium alloy products.
In the construction of aircraft, there is always the desire to make components lighter. Thus, the aircraft industry has started using sheet, plate, extrusion or forging components, for example, made from aluminum-lithium alloys. To further lighten the components, they can be selectively chemically milled. However, it has been found that conventional chemical milling baths produce roughened surfaces on the aluminum-lithium alloy parts and the problems attendent therewith. Thus, there is a great need for a chemical milling bath which can be used for selectively etching or milling aluminum-lithium alloy components which does not result in a roughened surface.
In accordance with these requirements, the present invention provides a bath suitable for etching or chemical milling of aluminum-lithium alloys which results in a remarkably smooth surface.